Perfluoroalkylthio norbornane compounds

ABSTRACT

The compounds disclosed are of the formula ##STR1## and the anhydrides thereof WHEREIN 
     R f  is a perfluoroalkyl group, 
     R&#39; is a divalent group of alkylene, ether, thioether or a sec.amine, 
     Y is oxygen, sulfur or an amine, and 
     R is hydrogen or alkyl. 
     R 3  is hydrogen or methyl 
     These compounds can be prepared by a free radical catalyzed addition of a polyfluoroalkylthiol to a 5-norbornene diacid or its derivative. They are useful in preparing surfactants when reacted with an amine.

DETAILED DISCLOSURE

This is a divisional of application Ser. No. 608,932 filed on Aug. 29, 1975, now U.S. Pat. No. 3,989,725.

The compounds of this invention are perfluoroalkylthio norbornane derivatives of the formulae ##STR2## wherein X is independently oxygen or the group > NR,

Y is independently oxygen, sulfur or the group > NR

R is independently hydrogen or alkyl of 1 to 24 carbons or each group - YR is independently a halogen

R' is a divalent radical of the formulae --C_(n) H_(2n) --; --C_(n) H_(2n) SC_(n) H_(2n) --, --C_(n) H_(2n) OC_(n) H_(2n) -- and ##STR3## WHERE N IS 1 TO 12 AND R² is hydrogen or alkyl of 1 to 6 carbons, R³ is hydrogen or methyl

R_(f) is a straight or branched chain perfluoroalkyl of 1 to 18 carbon atoms or said perfluoroalkyl substituted by a perfluoroalkoxy group of 2 to 6 carbon atoms.

The anhydride or diacid compounds of this invention are useful in the preparation of perfluoroalkyl group containing polyesters or polyamides. In preparing these polymers the above compounds are employed as the known anhydrides and diacids. The anhydrides or diacid compounds, when converted to simple metal salts, show pronounced surface activity in aqueous media. Therefore they are useful as wetting or dispersion agents.

The exact nature of the group R_(f) is not of critical importance as far as the compounds of this invention are concerned. For the sake of illustration, however, this group can be represented by such formulae as --C_(p) F_(2p+1) and --C_(q) F_(2q) O_(p) F_(2p+1) where p is 1 to 18 and preferably 6 to 12 and q is 2 to 8.

The group R' is a divalent radical of the formulae --C_(n) H_(2n), --C_(n) H_(2n) SC_(n) H_(2n) --, --C_(n) H_(2n) --O--C_(n) H_(2n) -- or ##STR4## wherein n is 1 to 12 and preferably 1 to 4, R² is hydrogen or alkyl of 1 to 6 carbons. R' is preferably --C_(n) H_(2n) -- where n is from 2 to 6.

The R groups are independently hydrogen or alkyl of 1 to 24 carbons and preferably of 1 to 6 carbons. Thus where Y is oxygen and both R groups are hydrogen the resulting compound is a dicarboxylic acid. If one R group is hydrogen and the other is alkyl, the resulting compound is a half ester, and when both R groups are alkyl, the compound is a diester. If Y is sulfur then the corresponding thioacids or thioesters results. When Y is an > NR group then an amido or an alkyl substituted amido compound results, depending on the definition of R.

Where X is oxygen the resulting compound is an anhydride and when it is > NR an imide is obtained. The compounds of formula II encompass acid halides when -YR is a halogen selected from chlorine, bromine or fluorine. Either both -YR groups can be acid halides or one -YR can be an ester, acid or amide while the other is an acid halide.

The above represented compounds can be obtained by a free radical catalyzed addition of a polyfluoroalkylthiol of the formula R_(f) --R'--SH to a 5-norbornene diacid, anhydride or a derivative thereof having a formula ##STR5## The norbornene reactant may have endo or exo cis configuration or it may have trans configuration when one -YR group is endo and the other exo. Therefore the compounds may exist in an isomeric mixture. The configuration of the norbornene reactant is normally retained in the addition product.

The various norbornene derivatives are available commercially. They can also be prepared by the methods described below.

The Diels-Alder addition of maleic anhydride to cyclopentadiene gives only the endo adduct, 5-norbornene-endo,endo-2,3-dicarboxylic anhydride. When dimethyl maleate is employed as the dienophile, the analogous reaction gives dimethyl 5-norbornene-endo,endo-2,3-dicarboxylate. Since the reaction is stereospecific, dimethyl fumarate or fumaric acid provides the corresponding trans-adducs. These unsaturated substances are the starting materials for the new products of this invention. Alternative routes to many of these starting materials are also known. For example, the esters may be made from the 5-norbornene-2,3-dicarboxylic anhydrides, or the trans-adducts may be obtained from the cis-adducts, by isomerization. There is only one known way to obtain the exo-anhydride, which is by isomerization of the endo-anhydride, but from 5-norbornene-exo,exo-2,3-dicarboxylic acid anhydride the whole series of related derivatives may then be prepared.

The two alternative routes to exo-5-(1,1,2,2-tetrahydroperfluorodecylthio)-endo,endo-2,3-dicarboxylic acids are shown below: ##STR6##

In a similar fashion the acids, esters, amides or alcohols of this invention can be prepared from the corresponding norbornene derivative in the manner most suitable to the purpose. The anhydride is particularly useful as it is readily converted to a large number of new compounds in high yield. There may be instances where the properties of the desired final product are such that it is more practical to follow one or the other procedure. Also, the precursor of the final product may be very difficult or impossible to prepare by a given route, but may be obtained by an alternate route. For example, the sodium salts of 5-norbornene-endo,endo-2,3-dicarboxylic acid are not readily obtained from the Diels-Alder reaction, but can be made from the adduct once the maleic anhydride-cyclopentadiene reaction has been done.

Other examples of the flexibility of approach which this invention affords, include the preparation of half esters either directly by radical addition of the perfluoroalkyl thiol to the norbornene dicarboxylic acid half ester, or by reaction of the exo-5-(1,1,2,2-tetrahydroperfluoroalkylthio)-norbornene-2,3-anhydride 2,3-anhydride with an alcohol; or the preparation of exo-5-(1,1,2,2-tetrahydroperfluoroalkylthio)-norbornene-2,3-dicarboxylic acid imide either from the corresponding amic acid or directly by radical addition of the thiol to the imide, in analogy to the two paths shown above for the dicarboxylic acids.

Further variations in procedure which have been found advantageous are choice of solvent, reaction in bulk without added solvent, choic of radical initiator and reaction time and temperature. Of course, these variables are not all independent of each other. In the large number of examples which are in this specification, these variations are amply demonstrated.

Specific examples which describe alternate processes are Example 3, for the preparation of exo-5-(1,1,2,2-tetrahydroperfluorodecylthio)-endo,endo-2,3-norbornane dicarboxylic acid, Examples 5 and 6 for the preparation of monomethyl ester of this acid and Examples 7 and 8 for the preparation of the imide of this acid.

The perfluoroalkyl thiols employed in the preparation of the compounds of this invention are well known in the prior art. For example, thiols of the formula R_(f) R¹ --SH have been described in a number of U.S. Pat. Nos. including 2,894,991; 2,961,470; 2,965,677; 3,088,849; 3,192,190; 3,544,663 and 3,655,732.

Thus, U.S. Pat. No. 3,655,732 discloses mercaptans of formula

    R.sub.f --R.sup.1 --SH

where

R¹ is alkylene of 1 to 16 carbon atoms and R_(f) is perfluoroalkyl and teaches that halides of formula R_(f) --R¹ --hal are well known; reaction of R_(f) I with ethylene under free-radical conditions gives R_(f) (CH₂ CH₂)_(a) I while reaction of R_(f) CH₂ I with ethylene gives R_(f) CH₂ (CH₂ CH₂)_(a) I as is further taught in U.S. Pat. Nos. 3,088,849; 3,145,222; 2,965,659 and 2,972,638.

U.S. Pat. No. 3,655,732 further discloses compounds of formula

    R.sub.f --R'--X--R"--SH

where

R' and R" are alkylene of 1 to 16 carbon atoms, with the sum of the carbon atoms of R' and R" being no greater than 25; R_(f) is perfluoroalkyl of 4 through 14 carbon atoms and X is --S-- or --NR'"-- where R'" is hydrogen or alkyl of 1 through 4 carbon atoms.

U.S. Pat. No. 3,544,663 teaches that the mercaptan

    R.sub.f CH.sub.2 CH.sub.2 SH

where

R_(f) is perfluoroalkyl of 5 to 13 carbon atoms, can be prepared by reacting the perfluoroalkyl alkylene iodide with thiourea or by adding H₂ S to a perfluoroalkyl substituted ethylene (R_(f) --CH═CH₂), which in turn can be prepared by dehydrohalogenation of the halide R_(f) --CH₂ CH₂ --hal.

The reaction of the iodide R_(f) --R¹ --I with thiourea followed by hydrolysis to obtain the mercaptan R_(f) --R¹ SH is the preferred synthetic route. The reaction is applicable to both linear and branched chain iodides. Many useful perfluoroalkoxyalkyl iodides are described in Australian Application 36963 filed April 24, 1968, of general formula

    (CF.sub.3).sub.2 CFO CF.sub.2 CF.sub.2 (CH.sub.2 CH.sub.2).sub.m I

where

m is 1-3.

Particularly preferred herein are the thiols of formula

    R.sub.f CH.sub.2 CH.sub.2 SH

where

R_(f) is perfluoroalkyl of 6 to 12 carbon atoms. These R_(f) --thiols can be prepared from R_(f) CH₂ CH₂ I and thiourea in very high yield.

Illustrative examples of prepferred perfluoroalkylalkylenethiols are ##STR7##

Especially preferred perfluoroalkylalkylenethiols are

    C.sub.6 F.sub.13 CH.sub.2 CH.sub.2 SH

    c.sub.8 f.sub.17 ch.sub.2 ch.sub.2 sh

    c.sub.10 f.sub.21 ch.sub.2 ch.sub.2 sh

and mixtures thereof.

The free radical initiators that can be employed in the reaction are azo-nitriles and azo-derivatives which dissociate into alkyl- or aryl-radicals at reaction temperatures. The best known example of an azo-nitrile is 2,2'-azobisisobutyronitrile and the dissociation providing the required alkyl-radical is shown as follows: ##STR8##

Other azo-nitriles are azo-derivatives which can be used are described in J. Brandrup and E. H. Immergut, Polymer Handbook (John Wiley & Sons) 1965 pages II-3 to II-14 and include, for example

2-cyano-2-propyl-aza-formamide

2,2'-azo-bis-isobytyronitrile

2,2'-azo-bis-2-methylpropionitrile

1,1'-azo-bis-1-cyclobutanenitrile

2,2'-azo-bis-2-methylbutyronitrile

4,4'-azo-bis-4-cyanopentanoic acid

1,1'-azo-bis-1-cyclopentanenitrile

2,2'-azo-bis-2-methylvaleronitrile

2,2'-azo-bis-2-cyclobutylpropionitrile

1,1'-azo-bis-1-cyclohexane nitrile

2,2'-azo-bis-2,4-dimethylvaleronitrile

2,2'-azo-bis-2,4,4-trimethylvaleronitrile

2,2'-azo-bis-2-benzylpropionitrile

1,1'-azo-bis-1-cyclodecane nitrile

azo-bis-(1-carbomethoxy-3-methylpropane)

phenyl-azo-diphenylmethane

phenyl-azo-triphenylmethane

azo-bis-diphenylmethane

3-tolyl-azo-triphenylmethane

Certain peroxide-initiators can also be useful in preparing the compounds of the present invention. These peroxide-initiators als decompose instantly into alkyl- or aryl- radicals. The alkyl- or aryl- radical is obtained either by instantaneous decomposition or by a rearrangement reaction of the primary decomposition products of the peroxide compound. Of the peroxides, the aliphatic acyl peroxides are, for example, most useful and one preferred aliphatic peroxide is acetyl peroxide. The decomposition of this compound into alkyl-radicals can be set out as follows: ##STR9## Reaction II follows Reaction I instantaneously. In the presence of iodine, only CH₃ I is isolated; proof of the instantaneous formation of the methyl radical. In addition to acetyl peroxide, lauroyl peroxide and decanoyl peroxides containing up to 18 carbon atoms are also useful as initiators. Such peroxide compounds include propionyl peroxide, butytyl peroxide, isobutryl peroxide, cyclobutaneacetyl peroxide, heptanoyl peroxide, caprylyl peroxide, cyclohexane acetyl peroxide, nonanoyl peroxide, myristoyl peroxide, stearyl peroxide and the like.

The free radical initiator is employed in the amounts of from 0.01 to 0.5 moles per mole of the norbornene starting compound and more preferably from 0.02 to 0.1 moles. The reaction is carried out at a temperature of from about 40° C to about 150° C either in bulk or in an inert solvent which does not interfere with the reaction. Illustrative examples of appropriate solvents are hydrocarbon solvents such as benzene, toluene, cresol, xylene, cyclohexane, pentane, hexane. Other solvents that may be also employed are ethyl acetate, dioxane, acetone, dimethylformamide, dimethylsulfoxide, pyridine, dimethylsulfone, tetrahydrofuran, chloroform, nitrobenzene, cyclohexanone.

The addition reaction can be also carried out without the initiator, but then the reaction must be carried out at a higher temperature, such as 150° C to 200° C. It is also possible to utilize ultraviolet radiation either alone or in combination with a free radical initiator. To accomplish the reaction under these conditions the reaction temperature may range from 10° to about 150° C.

Preferably the reaction is carried out in bulk, without a solvent medium, and in the presence of a free radical initiator, especially 2,2'-azo-bis-isobutyronitrile.

As noted above, 5-norbornene-2,3-endo, endo-dicarboxylic acid anhydride is available commercially. The corresponding esters can be prepared according to known methods, for example the dimethyl and the diethyl esters can be prepared by the method described by Morgan et al, J. Am. Chem. Soc. 66, 404 (1944) and Bauer et al, J. Org. Chem., 26, 1106 (1961).

The half alkyl esters can be prepared by the method of L. M. Rice and E. E. Reid, J. Am. Chem. Soc., 74, 3955 (1952), or H. M. Walton, J. Org. Chem., 22, 308 (1957). 5-Norbornene-2,3-exo, endo-dicarboxylic acid can be prepared by the method of H. Koch, J. Kotlan and H. Markut, Monatsh., 96, 1646 (1965) or of J. Sauer, H. Wiest and A. Mielert, Chem. Ber., 97. 3183 (1964). N-phenyl, N-tolyl and N-benzylimides of 5-norbornene-2,3-endo, endo (or exo, exo)-dicarboxylic acids can be prepared by the method of M. S. Morgan, R. S. Tipson, A. Lowy and W. E. Baldwin, J. Am. Chem. Soc., 66, 404 (1944). Many of these 5-norbornene-2,3-dicarboxylic acid derivatives can be prepared by the Diels-Alder reaction, as described by M. C. Kloetzel, Org. Reactions, Vol. IV, 1, (1948).

Presented below are examples to illustrate further the present invention without introducing any limitation.

EXAMPLE 1 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluorooctylthio)-endo,endo-2,3-Norbornane Dicarboxylic Acid Anhydride

In a 100 ml round bottom flask fitted with a nitrogen inlet tube, a reflux head connected to a cold trap, and stirred by magnet bar was placed 1,1,2,2-tetrahydroperfluorooctanethiol (20.0 g, 0.0526 mole), benzene (25 ml) and 5-norbornene-2,3-endo, endo-dicarboxylic acid anhydride (8.20 g, 0.0500 mole). The solution was heated under a nitrogen atmosphere to 61° in an oil bath, as azobisisobutryronitrile (ABN, 0.284 g, 1.73 mmole) was added. The reaction temperature increased to about 70° C and was kept at 73°-76° C for 17 hours. The solid adduct was collected on a Buchner funnel, rinsed with ligroine and pressed dry. The filtrate was evaporated and the solid combined with the filtered solid. The yield of the product was quantitative. The product recrystallized from carbon tetrachloride had a m.p. of 103°-105° C and from ethyl acetate a m.p. of 107°-108° C. I.R. spectrum and NMR were consistent with the structure of the above named compound.

Anal. Calcd for C₁₇ H₁₃ F₁₃ O₃ S: C, 37.51; H, 2.41; F, 45.38; S, 5.89. Found: C, 37.37; H, 2.27; F, 44.64; S, 5.75.

Table I below summarizes additional compounds prepared by the above described procedure, including the compound described above. Pure Adduct (R_(f) ═C₈ F₁₇, Example 4) was isolated directly from the reaction solvent, when a mixture of ethyl acetate and ligroine was used.

                                      TABLE I                                      __________________________________________________________________________     Preparation of exo-5-(1,1,2,2-Tetrahydroperfluoroalkylthio)-endo,endo-2,3-     Norbornane Dicarboxylic Anhydrides.                                             ##STR10##                                                                     Reactants                                                                                        Norbornene                                                   R.sub.f CH.sub.2 CH.sub.2 SH                                                                     derivative                                                                            Solvent                                                                               ABN Conditions                                                                            Product                             Ex.       wt      wt            wt  Time                                                                              Temp                                                                               Conv                                                                               M.P.   Recrystallizing          NO.                                                                               R.sub.f                                                                               mmol    mmol   ml     mmole                                                                              hr ° C                                                                         %   ° C                                                                            Solvent                  __________________________________________________________________________     1  C.sub.6 F.sub.13                                                                      20.0g   8.20g  benzene                                                                               0.284g                                                                             17 73-76°                                                                      100 107-108°                                                                       ethyl acetate                      (52.6)  50.0   25     1.73                                           2  C.sub.6 F.sub.13                                                                      9.90g   4.10g  benzene                                                                               .0871g                                                                             5.2                                                                               74-80°                                                                      100 107.5-108°                                                                     ligroine-                          (26.04) 24.97  20     .531                  ethyl acetate            3  C.sub.8 F.sub.17                                                                      9.60g   3.28g  benzene                                                                               .0821g                                                                             6  73-83°                                                                      92  128-129°                                                                       benzene or                         (20.0)  20.0   30     .500                  ethyl acetate            4  C.sub.8 F.sub.17                                                                      96.04g  32.53  EtAc(75ml)                                                                            0.6568g                                                                            18 73-77°                                                                      89  129-130°                                                                       (from reaction                     (200.0  200.0  ligroine                                                                              4.00                  mixture)                                          (200ml)                                               5  C.sub.7 F.sub.15                                                                      6.25g   2.38g  benzene                                                                               .0821g                                                                             6  76-85°                                                                      91  111-113.5°                                                                     benzene                            (14.5)  14.5   20     .500                                           6  C.sub.10 F.sub.21                                                                     29.07g  8.20° g                                                                        benzene                                                                               .164g                                                                              6  79-82°                                                                      98  140-143°                                                                       ethyl acetate                      (50.10) 50.00  50     1.00                                           7  (CF.sub.3).sub.2 CFOCF.sub.2 CF.sub.2                                                         3.79g  benzene                                                                               .100g                                                                              6  69-74°                                                                      100 85°                                                                            ligroine                                   2.31   25ml   .609                                              8.00g                                                                          (23.1)                                                                      8  (CF.sub.3).sub.2 CFO(CF.sub.2 CF.sub.2).sub.n                                                 3.44g  benzene                                                                               0.100g                                                                             6  70-82°                                                                      93  91-94°                                                                         benzene                                    21.0   20ml   0.609                                             n=6,8 (mixture)                                                                12.0g, (20.98mmole)                                                         9  CF.sub.3 (CF.sub.2).sub.n                                                                     6.56g  benzene                                                                               .100g                                                                              7  72-75°                                                                      100 99-111°                                    40.0   45ml   .609           (Unpurified)                       n=6,8,10                                                                       19.20g. (40.0mmoles)                                                           n=6, 3.80g (10.0mmole)                                                         n=8, 9.60g (20.0mmole)                                                         n=10, 5.80g (10.0mmole)                                                     __________________________________________________________________________

EXAMPLES 10-12 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluoroalkylthio)-exo,exo-2,3-Norbornane Dicarboxylic Acid Anhydrides.

Following the general procedure of Example 1 the adducts from the 1,1, 2,2-tetrahydroperfluoroalkanethiols and 5-norbornene-exo,exo-2,3-dicarboxylic acid anhydride were prepared, as listed in Table II. The exo anhydride was prepared from the endo anhydride as described below.

Part A (Preparation of the Anhydride) Isomerization of exo-5-Norbornene-endo,endo-2,3-Dicarboxylic Acid Anhydride to exo-5-Norbornene-exo,exo-2,3-Dicarboxylic Acid Anhydride.

Following the procedure given by D. Craig, Journal of the American Chemical Society, Vol. 73, page 4889 (1951), the endo anhydride (76.5 g, 0.466 mol) was heated in a flask immersed in an oil bath at 180°-197° C, while stirring by a magnet bar under a slow purge of nitrogen, for three hours. Samples were removed after each hr. The hot, brown liquid was poured cautiously into 150 ml of benzene, a small amount of activated carbon added and after stirring for a few minutes, filtered while hot. The solution was chilled to 5° C while stirring and the solid product (from 200 ml) collected and rinsed once with benzene at room temperature. The first crystal crop, wt. 25.65 g, mp. 125°-135°, was redissolved in 100 ml of benzene, and pure exo anhydride crystallized at room temperature as long shafts, wt. 16.64 g, mp. 139°-141.5°. Successive crystal fractions yielded 38.94 g. of additional exo anhydride. These fractions contained an increasing amount of endo anhydride and could be reheated to isomerize again to the exo isomer. The ratio of exo to endo was conveniently followed by integrated areas of proton resonances in the nmr spectra.

                                      TABLE II                                     __________________________________________________________________________     Preparation of exo-5-(1,1,2,2-Tetrahydroperfluoroalkylthio)-exo,exo-2,3-No     rbornane Dicarboxylic Acid Anhydrides                                          __________________________________________________________________________      R.sub.f CH.sub.2 CH.sub.2 SH                                                                       ##STR11##                                                                                       ##STR12##                                Reactants                                                                                   Norbornene                                                        R.sub.f CH.sub.2 CH.sub.2 SH                                                                derivative  ABN  Conditions                                                                            Product                                   Ex.      wt  wt     Solvent                                                                             wt   Time                                                                              Temp                                                                               Conv     Recrystallizing                  No.                                                                               R.sub.f                                                                              mmol                                                                               mmol   ml   mmol hr ° C                                                                         %   M.P. Solvent                          __________________________________________________________________________     10 CF.sub.3 (CF.sub.2).sub.n                                                            20.0g                                                                              5.75g  benzene                                                                             0.100g                                                                              6  70-83°                                                                      100 89-100°                                                                      11.13g                              n=5,7,9                                                                              (44.4)                                                                             35.0   25 ml                                                                               (.609)          79-91°                                                                       6.9g                             11 CF.sub.3 (CF.sub.2).sub.7                                                            9.60g                                                                              2.96g  benzene                                                                             0.0821g                                                                             5  67-73°                                                                      95.8                                                                               104-106°                                                                     eth. acet./                               (20.0)     10 ml                                                                               (0.500)              ligroine                         12 CF.sub.3 (CF.sub.2).sub.5                                                            7.60g                                                                              2.96g  same same 5.5                                                                               same                                                                               93.7                                                                               72-73°                                                                       ligroine                                  (20.0)                                                                             18.0                                                              __________________________________________________________________________

EXAMPLE 13 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluorodecylthio)-endo,endo-2,3-Norbornane Dicarboxylic Acid.

Following the procedure described in Example 1, 1,1,2,2-tetrahydroperfluorodecanethiol (9.60 g, 0.0200 mole), 5-norbornene-2,3-endo,endo-dicarboxylic acid (3.64 g, 0.0200 mole) and ABN (0.1200 g, 0.730 mole) were allowed to react in 50 ml of ethyl acetate. At 75° the solution became clear and it was kept at 73°-75° for 8 hours. The solvent was allowed to evaporate at room temperature and the solid (11.74 g, 89% of theory) melted over the range of 110°-130°. A portion of the solid product (1.2824 g, 1.936 mmol) was dissolved in 28.92 ml of 0.1000 N NaOH solution and 15 ml of ethanol at 40°. The foamy solution of the sodium salt was acidified with 5 ml of 6N HCl and the precipitated white solid acid was air dried (1.1545 g, 90% recovery, mp 133° C decomposition). Another portion of the product was recrystallized from ligroine containing sufficient ethyl acetate to clear the solution. Pure crystalline dicarboxylic acid was obtained melting at 137°-138° C (decomposition with gas evolution). IR and NMR spectra were consistent with the structure of the above-named compound.

The product was also prepared from the anhydride of Example 1 (Table I, Example 3, 1.2884 g, 2.000 mmol), sodium hydroxide (30.00 ml of 0.1000N solution, 3.000 mmol) and 5 ml of ethanol, heated at 40°-50° for 2 hr, acidified with 2.5 ml of 6N HCl; wt, 1.289 g, 100% yield, mp 117°-122°. An IR spectrum showed the COOH bands at 1710 and 1655 cm⁻¹.

Anal. Calcd for C₁₉ H₁₅ F₁₇ O₄ S: C, 34.45; H, 2.28; F, 48.77. Found: C, 34.36; H, 2.23; F, 48.29.

EXAMPLE 14 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluorodecylthio)-exo,endo-2,3-Norbornane Dicarboxylic Acid Isomers, i.e., trans Diacid. ##STR13##

A mixture of 1,1,2,2-tetrahydroperfluorodecanethiol (12.00 g, 0.0250 mol), 5-norbornene-2-exo-3-endo-dicarboxylic acid (3.64 g, 0.0200 mol, mp 186°) and ABN (0.1200 g, 0.7000 mmol) were allowed to react in 25 ml of ethyl acetate. After 15 minutes at 72°-73° the slurry dissolved and an exotherm carried the temperature to 78°. After 2.5 hr at 75°-78° the clear solution was allowed to stand at 25°. Crystals of the product (4.806 g, mp 164°-166°) were collected. The hot filtrate was diluted with 15 ml of ligroine (bp 60°-70°) and when cool, deposited solid (8.274 g, mp 116°-128°, total yield, 100%).

Anal. Calcd for C₁₉ H₁₅ F₁₇ O₄ S: C, 34.45; H, 2.28; F, 48.77. Found: C, 34.28; H, 2.24; F, 48.83.

EXAMPLE 15 Preparation of Dimethyl 5-exo-(1,1,2,2-Tetrahydroperfluorooctylthio)-2,3-endo,endo-Norbornane Dicarboxylate

A Fischer-Porter aerosol tube was charged with 1,1,2,2-tetrahydroperfluorooctanethiol (10.65 g, 0.02800 mole), dimethyl 5-norbornene-2,3-endo,endo-dicarboxylate (5.2 g, 0.0248 mole) and ABN (0.164 g, 1.00 mole), cooled to -78°, evacuated and filled with nitrogen three times and heated at 70.0° in an oil bath for 16 hr. From the reaction mixture 0.35 g of the thiol was recovered upon distillation at 125° C (0.10 mm). The remaining oil residue (14.8 g, 100% yield) was the desired product. IR and NMR spectra were consistent with the structure of the named compound.

Anal. Calc'd for C₁₉ H₁₉ F₁₃ O₄ S: C, 38.65; H, 3.24; F, 41.84; S, 5.48. Found: C, 38.32; H, 3.17; F, 41.46; S, 5.78.

In a similar fashion the following new acid esters of 5-exo-(1,1,2,2-tetrahydroperfluoroalkylthio)-x,x-2,3-norbornane dicarboxylic acid esters listed in Table III were prepared.

                                      TABLE III                                    __________________________________________________________________________     Preparation of exo-5-(1,1,2,2-Tetrahydroperfluoroalkylthio)-x-x-2,3-Norbor     nane Dicarboxylic Acid Esters                                                   ##STR14##                                                                      ##STR15##                                                                      ##STR16##                                                                      ##STR17##                                                                     Reactants                                                                                     Norbornene                                                                            Conditions       Product                                                Derivative  ABN                 Recrystal-                      Ex.                                                                               R.sub.f CH.sub.2 CH.sub.2 SH                                                           wt  wt     Solvent                                                                             wt   Time                                                                              Temp                                                                               Conv    lizing                          No.                                                                               R.sub.f mmol                                                                               mmol   ml   mmol hr ° C                                                                         %   M.P.                                                                               Solvent                         __________________________________________________________________________     16 CF.sub.3 (CF.sub.2).sub.n                                                               20.0 g                                                                             8.40 g (2b)                                                                          neat  0.100 g                                                                            6  70°                                                                         97.5                                                                               *   --                                 n=6,8,10                                                                               (44.4)                                                                             (40.4)      (0.609)                                             17 CF.sub.3 (CF.sub.2).sub.7                                                               10.0 g                                                                             4.20 g (2b)                                                                          neat  0.0500g                                                                            13 69-74°                                                                      94.5                                                                               65-69°                                                                      Ligroine                                   (20.8)                                                                             (20.0)      (0.345)                                             18 CF.sub.3 (CF.sub.2).sub.n                                                               20.0 g                                                                             7.85 g (2a)                                                                          CH.sub.3 OH                                                                          0.100 g                                                                            6  69-74°                                                                      97  59-62°                                                                      --                                 n=6,8,10                                                                               (44.4)                                                                             (40.0) 2.0 ml                                                                              (0.609)                                             19 CF.sub.3 (CF.sub.2).sub.7                                                               9.60 g                                                                             7.389 g (2a)                                                                         CH.sub.3 OH                                                                          0.125 g                                                                            6  75-78°                                                                      100 74-85°                                                                      --                                         (20.0)                                                                             (45.0) 10.0 ml                                                                             (0.761)                                             __________________________________________________________________________

EXAMPLES 20 Preparation of Methyl Hydrogen exo-5-(1,1,2,2-Tetrahydroperfluorodecylthio)-endo,endo-2,3-Norbornane Dicarboxylate.

Exo-5-(1,1,2,2-tetrahydroperfluorodecylthio)-endo,endo-2,3-norbornane dicarboxylic anhydride (Example 4, Table I, 12.88 g, 20.00 mmol) and methanol (32.0 g, 1.00 mol) were heated under reflux at 65° while stirring for one hour to give a clear solution of the half methyl ester. After standing several hours excess methanol was removed at the water pump, while heating to 72°. The white solid (13.21 g, 97.7% yield) melted over the range of 77°-85° and decomposed, gas evolving at 150°. Examination by IR and NMR spectra revealed that two isomers were present and that they were identical to the isomeric adduct mixture obtained by the alternate procedure given in Table III, Example 19.

Anal. Calc'd for C₂₀ H₁₇ F₁₇ O₄ S: C, 35.51; H, 2.53; F, 47.75. Found: C, 35.31; H, 2.49; F, 46.97.

EXAMPLE 21 Preparation of Methyl exo-5-(1,1,2,2-Tetrahydroperfluorodecylthio)-endo-Carboxylate-endo-N,N-Diethylamide.

The product of Example 20 (13.53 g, 20.0 mmol) and thionyl chloride (14.2 g, 120 mmol) was heated at 60° for one hour, and excess thionyl chloride removed at the water pump. The resulting intermediate acid chloride was divided in half. Benzene (30 ml) was added to half and at 5°, diethylamine (2.92 g, 40.0 mmol) was added slowly while stirring. After standing for two hours, the reaction mixture was worked up as in previous examples and the product isolated in 90.9% yield.

Analysis for: C₂₄ H₂₇ F₁₇ NO₃ S

Calculated: C, 39.35; H, 3.72; F, 44.09; N, 1.91; S, 4.38.

Found: C, 39.63; H, 3.46; F, 43.61; N, 1.92; S, 4.55.

EXAMPLE 22 Preparation of Methyl Hexylthio exo-5-(1,1,2,2-Tetrahydroperfluorodecylthio)-endo,endo-2,3-Dicarboxylate. ##STR18##

To half of the acid chloride prepared above, benzene (30 ml) was added and at 10°, a solution of 1-hexanethiol (1.18 g, 1.40 ml, 10.0 mmol) and pyridine (0.791 g, 0.80 ml, 10.0 mmol) in benzene (10 ml) was slowly added while stirring. After heating at reflux temperature (78°) for 15 hrs. the solvent was removed by distillation and the product was recovered as a colorless liquid residue, 5.63 g (72.5% yield). The structure was confirmed by IR and NMR.

Analysis for: C₂₆ H₂₉ F₁₇ O₃ S₂

Calculated: C, 40.2; H, 3.76; F, 41.59; S, 8.26.

Found: C, 41.4; H, 4.2; F, 40.0; S, 9.1.

EXAMPLE 23 Preparation of Hexylthio 5-exo-(1,1,2,2,-Tetrahydroperfluorodecylthio)-endo,exo-2,3-Dicarboxylate.

Exo-5-(1,1,2,2-tetrahydroperfluorodecylthio)-endo,exo-2,3-dicarboxylic acid (5.11g, 7.55 mmol) was converted to the endo, exo diacid chloride (5.10g). Benzene (30 ml) was added to the residual oil and a solution of 1-hexanethiol (1.80g, 15.1 mmol) and pyridine (1.20g, 1.20 ml, 15.1 mmol) in 10 ml of benzene was added slowly while stirring at 10°. After standing at room temperature for two hours the reaction mixture was filtered, rinsed with 10 ml of benzene and evaporated off to yield 3.6g of solid dihexylthio ester.

Analysis for: C₃₁ H₃₉ F₁₇ S₃ O₂

Calculated: C, 43.15; H, 4.56; F, 37.4; S, 11.15.

Found: C, 43.4; H, 4.8; S, 12.2.

EXAMPLE 24 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluorodecylthio)-endo,endo-2,3-Norbornane Dicarboxylic N,N-Diethylamide.

To the endo diacid chloride (5.10g, 7.55 mmol) prepared from the endo dicarboxylic acid of Example 13 is added benzene (30 ml), and while stirring at 5°, a solution of diethylamine (2.20g, 0.0302 mol) in benzene (10 ml) is slowly added. After standing overnight at room temperature the mixture is filtered, washed with water, extracted with ether and the extract washed with 5% Na₂ CO₃ solution and 2M HCl solution and dried over MgSO₄. The solvent is stripped off leaving a viscous oil.

EXAMPLE 25 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluoroalkylthio)-endo,endo-2,3-Norbornane Dicarboxylic N,N-Diethylamides.

5-Norbornene-endo,endo-2,3-dicarboxylic acid bis N,N-diethylamide, 2 is synthesized by the method of Koch, Kotlan and Markut, Monatshefte, 96, 1646 (1965). Following the general procedure of Example 15, free radical addition of a mixture of 1,1,2,2-tetrahydroperfluoroalkylthiols (19.20 g, 40.0 mmol) to the above prepared diethylamide (11.69 g, 40.0 mmol), initiated by ABN (0.100g, 0.609 mmol) in benzene (50 ml) at 70° for 8 hours gives solid product in good yield.

EXAMPLE 26 Preparation of exo-5-(1,1,2,2-Tetrahydroperfluoroalkylthio)-exo,endo-2,3-Norbornane Dicarboxylic N,N-Diethylamides.

To the endo,exo-diacid chloride prepared in Example 26 (5.60g, 0.008 mol) in benzene (50 ml) was added diethylamine (2.91 g, 0.00400 mol) in benzene (10 ml) at 25°. After standing overnight at room temperature the mixture was filtered, washed with water, extracted with ether and the extract washed with 5% Na₂ CO₃ solution and 2M HCl and dried over MgSO₄. The solvent was stripped off leaving a viscous oil (6.0g, 97% yield) which solidified, m.p. 65°-68.5°.

Analysis for: C₂₇ H₃₇ F₁₇ N₂ O₂ S

Calculated: C, 41.97; H, 4.30; F, 41.81; N, 3.63; S, 4.15.

Found: C, 41.87; H, 4.25; F, 42.10. 

What is claimed is:
 1. A compound having the formula ##STR19## wherein Y is independently oxygen or sulfur provided that at least one Y is sulfur,R' is a divalent radical of the formula --C_(n) H_(2n) --, --C_(n) H_(2n) --S--C_(n) H_(2n) --, --C_(n) H_(2n) --O--C_(n) H_(2n) -- or ##STR20## where n is 1 to 12 and R² is hydrogen or alkyl of 1 to 6 carbon atoms, R_(f) is a straight or branched chain perfluoroalkyl of 1 to 18 carbon atoms or said perfluoroalkyl substitited by a perfluoroalkoxy group of 2 to 6 carbon atoms, R³ is hydrogen or methyl and R is independently hydrogen or alkyl of 1 to 24 carbons.
 2. A compound of claim 1 wherein R' is --C_(n) H_(2n).
 3. A compound of claim 2 wherein n is 2, R_(f) is a perfluoroalkyl group of 6 to 12 carbon atoms or a mixture of such groups and R³ is hydrogen.
 4. A compound of claim 1 wherein both Y groups are sulfur.
 5. A compound of claim 2 wherein R³ is methyl.
 6. A compound of claim 3 wherein R_(f) is a perfluoroalkyl group of 6 to 12 carbon atoms or a mixture of such groups.
 7. A compound of claim 1 wherein one Y is oxygen and the other Y is sulfur.
 8. A compound of claim 6 wherein R_(f) is a perfluoroalkyl group of 6 to 12 carbon atoms or a mixture of such groups. 